The present invention relates to a regenerator for use in an ammonia absorption refrigerator.
Conventionally, a heater of smoke tube type is used for a regenerator in an ammonia absorption refrigerator.
More specifically, as shown in FIG. 11, the heater 101 comprises a cylindrical heater body 102 disposed below a rectifying column 111, a cylindrical combustion chamber 103 disposed in a lower portion of the heater body 102, heat transfer tubes 104 disposed above the combustion chamber 103, and an smoke passage 105 for introducing combustion gas resulting from combustion in the combustion chamber 103 into the heat transfer tubes 104.
In the aforesaid arrangement, the combustion gas from the combustion chamber 103 is introduced into the heat transfer tubes 104 via the smoke passage 105 so that a strong ammonia aqueous solution supplied into the heater body 102 is heated for separation of ammonia by evaporation thereof.
With the aforesaid arrangement, however, the heater of smoke tube type has a complicated construction, requiring much time for manufacture, inspection and maintenance thereof. This leads to a problem of increases in production costs and running costs.
It is therefore an object of the present invention to provide a regenerator for use in an ammonia absorption refrigerator which features lower production costs and easy maintenance.
In accordance with the present invention, there is provided a regenerator for use in an ammonia absorption refrigerator, the regenerator comprising a heater for heating an ammonia aqueous solution and a rectifying column for enriching ammonia in an ammonia solution-vapor mixture obtained in and introduced from the heater, wherein the heater comprises a heater body having a heating chamber, a burner disposed in a lower portion of the heating chamber, and a heat transfer tube bundle provided in a meandering arrangement above the burner within the heating chamber, the heat transfer tube bundle having an inlet and an outlet which are respectively connected to lower portions of the rectifying column via transfer pipes.
In accordance with another aspect of the invention, the heat transfer tube bundle of the heater of the regenerator having the aforesaid construction has an orifice provided at the inlet thereof and a fin provided on an outer circumferential surface thereof, and a lean pre-mixture combustion type ceramic burner is used as the burner, wherein the heat transfer tube bundle is exposed to flames of the burner.
The regenerator, in which the heater body is provided separately from the rectifying column, the lean pre-mixture combustion type ceramic burner is disposed in the lower portion of the heating chamber and the heat transfer tube bundle is provided in an meandering arrangement within the heating chamber, has a simple and compact construction, compared with a regenerator having a heater provided integrally with a rectifying column therebelow. This arrangement facilitates maintenance and inspection of the regenerator. Since the heater has a compact construction, the amount of the ammonia aqueous solution to be retained therein is reduced, thereby improving the safety.
In accordance with further another aspect of the invention, the rectifying column of the regenerator has a gas-liquid separation space provided in a lower portion of a column body for separating ammonia from the ammonia aqueous solution, and first and second pooling chambers separated by a partition wall of a predetermined height provided on the bottom of the column body, in order that an ammonia aqueous solution pooled in the first pooling chamber is introduced into the heater via one of the transfer pipes and the ammonia aqueous solution heated in the heater is introduced into the gas-liquid separation space above the second pooling chamber via the other transfer pipe, the rectifying column further having a baffle plate provided in the column body for guiding downward into the second pooling chamber the heated ammonia aqueous solution supplied into the gas-liquid separation space via the other transfer pipe.
With this arrangement, the lower portion of the column body of the rectifying column is partitioned by the partition wall into the separate pooling chambers in which the ammonia-rich aqueous solution supplied into the column body from an absorber and the weak ammonia aqueous solution resulting from vapor separation by the heating in the heater are respectively pooled. Therefore, the concentration of the weak ammonia aqueous solution taken out of the second pooling chamber can be kept constant. That is, the regeneration efficiency can be improved.